Little information is available about panic disorder in Black Americans. Available research suggests that panic disorder and hypertension often co- occur in this population, with stress playing an important role in both disorders. Research documenting increased autonomic arousal in response to stressors in the laboratory and naturalistic environment in individuals with panic disorder and individuals with essential hypertension has raised questions about the relationships between panic disorder and hypertension The proposed study examines heart rate and blood pressure reactivity and variability in Black females with panic disorder, Black females with panic disorder and mild (Stage 1) hypertension, Black females with mild (Stage 1) hypertension, and normotensive Black females. The specific aims of the proposed study are as follows: to investigate similarities and differences in physiologic response to stress in the laboratory setting among the four groups; to investigate similarities and differences in the variability of physiologic responses in the natural environment among the four groups; to examine the activities and emotions experienced by women in the four groups during the course of a normal day; to determine how variability in these activities and emotions may affect variability in physiologic responses during the course of a normal day; to investigate the relationships between hostility and competitiveness and physiologic response among the four groups. Eighty non-pregnant premenopausal Black females between the age of 18-51 will serve as subjects. Women will be screened using the Revised Anxiety Disorders Interview Schedule adapted for use with Black Americans, a medical screening and three casual blood pressure readings. Based upon screening results, women will be assigned to one of the four groups. In the second part of the study, women will participate in a laboratory reactivity segment and 24 ambulatory variability monitoring segment. BP and HR will be monitored in both segments. Information about daily hassles, hard-driving competitiveness, and hostility will also be obtained. The proposed study will contribute to the knowledge base on panic and Black Americans. Information from the proposed may have implications for the assessment and treatment of panic disorder in this population.